Comfortable air is flying out, outdoor air is sailing in.

It may surprise you to learn that your house is full of holes. But if your house is like most others, it has hundreds of small holes, and possibly a few large ones, left over from its original construction and later improvements. Each hole, small or large, is an air leak, through which air moves from inside the house to outside, and from outside the house to inside.

Air leaks are not necessarily a bad thing. In many homes, air leaks are the main source of fresh air for breathing. They also provide air for the safe combustion of fuels in some types of furnaces, water heaters, and fireplaces. But excessive air leakage makes a house drafty and uncomfortable, and expensive to heat and cool. In addition, air leaking into a house from the crawlspace, attic, and garage may carry pollutants, dust, and odors.

For these and other reasons, Air Sealing, the closing of holes and gaps in a house, should be a top priority whenever a home has comfort, air quality, or energy efficiency problems. How air sealing is performed depends on the size and location of an air leak. Large holes in the attic, for example, may be covered with plywood or sheet metal and sealed with caulk. Smaller holes and gaps are usually sealed with caulk or expanding foam, while ductwork is made airtight with a rubbery paste called mastic. Ideally, air sealing should be completed before insulation is added, but previously insulated homes can and should be air sealed.

The professionals at Vesta Home Performance have the training, experience, and tools to air seal your home quickly and properly. Using a blower door (a large, calibrated fan fit into a doorway), we depressurize the house to measure its total air leakage. While the blower door is running, the increased pressure magnifies the air leaks so our crew can quickly find and seal them. As the work proceeds, the blower door is periodically re-activated to monitor the reduction in air leakage and to ensure that sufficient leakage remains to provide adequate fresh air. (For homeowners who want maximum energy savings, air leakage can be reduced to an absolute minimum if a fan ventilation system is installed to supply fresh air.) After a day or two of air sealing, you will notice a remarkable change. Your home will stay warm longer (in winter) and cool longer (in summer), with fewer on/off cycles of your furnace and air conditioner. Your indoor air will be cleaner and more uniformly comfortable. Best of all, as your comfort and air quality goes up, your energy bills will go down.